To improve the tenderness and/or flavor of meat, such as beef, the meat can be aged to allow endogenous proteolytic enzymes to weaken structural and myofibrillar proteins. Typically meat is aged through refrigeration at temperatures just above freezing (e.g., 33-34 degrees Fahrenheit). In the aging process, a natural breakdown of the meat occurs during which the muscles at first shorten and stiffen but then become tenderer over time. Chemical changes occurring in the muscle and fat during the aging process can result in meat that is desired because of flavor, aroma, and/or tenderness that develop. Meat can be aged by a wet aging or a dry aging process.
Wet aging of meat is faster and less expensive than dry aging. Wet aging generally includes vacuum packaging meat in a plastic material to seal the meat so that moisture cannot escape from within the package and the meat is surrounded by and absorbs its juices. Wet aging, however, can produce a distinctive taste.
Dry aging of meat, by contrast, is more time consuming than wet aging. Dry aging generally includes leaving the meat exposed to oxygen in a controlled, cold environment, and allowing the meat to breathe. Due to the exposure of the meat to oxygen, the outer portion of the meat can mold or harden and that portion of the meat can be trimmed. Further, over time, the meat can lose weight and shrink. For instance, prior to reaching the store that sells the meat to the consumer, the meat may have lost a third or more of its weight as moisture loss (e.g., shrinkage).